硫酸化多糖的巨大结构多样性需要同样多样的酶阵列,称为多糖磺基转移酶(PST)。PST存在于生活的所有王国中,包括藻类,真菌和古细菌,它们的硫酸化途径相对未被探索。硫酸多糖具有抗炎,抗凝血和抗癌特性,具有巨大的治疗潜力。目前使用Pfam对PST的鉴定主要集中在糖胺聚糖(GAG)磺基转移酶的鉴定上,因为它们在细胞通讯中具有关键作用,细胞外基质的形成和凝血。因此,我们对非GAGPST结构和功能的了解仍然有限。主要的磺基转移酶家族,磺基转移酶_1和磺基转移酶_2显示出广泛的同源性,应该能够捕获各种各样的磺基转移酶,但仅限于非GAGPST序列注释。此外,序列注释进一步受到PST生化分析不足的限制。现在有高通量和强大的硫基转移酶测定法,如比色PAPS(3'-磷酸腺苷5'-磷酸硫酸盐)偶联测定法,用于比例PAP(3'-磷酸腺苷-5'-磷酸)检测的基于铕的荧光探针,和用于活性和产物分析的NMR方法。这些技术提供实时和直接的测量,以增强整个生命树的硫酸化多糖的功能注释和后续分析,以改善推定的PST识别和功能表征。PST序列的改进注释和生化分析将增强PST在生物医学和生物技术领域的实用性。
The vast structural diversity of sulfated polysaccharides demands an equally diverse array of enzymes known as polysaccharide
sulfotransferases (PSTs). PSTs are present across all kingdoms of life, including algae, fungi and archaea, and their sulfation pathways are relatively unexplored. Sulfated polysaccharides possess anti-inflammatory, anticoagulant and anti-cancer properties and have great therapeutic potential. Current identification of PSTs using Pfam has been predominantly focused on the identification of glycosaminoglycan (GAG)
sulfotransferases because of their pivotal roles in cell communication, extracellular matrix formation and coagulation. As a result, our knowledge of non-GAG PSTs structure and function remains limited. The major sulfotransferase families, Sulfotransfer_1 and Sulfotransfer_2, display broad homology and should enable the capture of a wide assortment of
sulfotransferases but are limited in non-GAG PST sequence annotation. In addition, sequence annotation is further restricted by the paucity of biochemical analyses of PSTs. There are now high-throughput and robust assays for
sulfotransferases such as colorimetric PAPS (3\'-phosphoadenosine 5\'-phosphosulfate) coupled assays, Europium-based fluorescent probes for ratiometric PAP (3\'-phosphoadenosine-5\'-phosphate) detection, and NMR methods for activity and product analysis. These techniques provide real-time and direct measurements to enhance the functional annotation and subsequent analysis of sulfated polysaccharides across the tree of life to improve putative PST identification and characterisation of function. Improved annotation and biochemical analysis of PST sequences will enhance the utility of PSTs across biomedical and biotechnological sectors.